Power management for audience measurement meters

ABSTRACT

Power management methods, apparatus and articles of manufacture for audience measurement meters are disclosed. Example methods disclosed herein include obtaining presentation device state data representing an activation state of a media presentation device that is to present received media and is monitored by an audience measurement meter, the presentation device state data including time information. Such disclosed example methods also include determining whether to fault audience measurement data reported by the audience measurement meter based on the presentation device state data and power outage information determined from the audience measurement data.

RELATED APPLICATION(S)

This patent arises from a continuation of U.S. patent application Ser.No. 13/149,500 (now U.S. Pat. No. 8,924,994), which is entitled “POWERMANAGEMENT FOR AUDIENCE MEASUREMENT METERS” and which was filed on May31, 2011. U.S. patent application Ser. No. 13/149,500 is herebyincorporated by reference in its entirety.

FIELD OF THE DISCLOSURE

This disclosure relates generally to audience measurement and, moreparticularly, to power management for audience measurement meters.

BACKGROUND

Prior audience measurement systems include audience measurement metersthat may operate continuously to ensure accurate monitoring of monitoredmedia presentation devices, which may present media content at any time.As such, an audience measurement meter in one of these prior systems mayconsume power continuously, even when the associated media presentationdevice being monitored is inactive. Furthermore, in such a prior system,measurement data provided by the audience measurement meter may befaulted (e.g., considered invalid and/or discarded) for an entiremonitoring period, such as an entire day, if the audience measurementmeter experiences any loss of power and/or other outage for any durationduring the monitoring period.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is block diagram of an example audience measurement systememploying power management for audience measurement meters as describedherein.

FIG. 2 is a block diagram of an example state monitor that may be usedto implement the example audience measurement system of FIG. 1.

FIG. 3 is a block diagram of a first example audience measurement meterthat may be used to implement the example audience measurement system ofFIG. 1.

FIG. 4 is a block diagram of a second example audience measurement meterthat may be used to implement the example audience measurement system ofFIG. 1.

FIG. 5 is a block diagram of an example data processing facility thatmay be used to implement the example audience measurement system of FIG.1.

FIG. 6 is a flowchart representative of example machine readableinstructions that may be executed to implement power managementprocessing in the example state monitor of FIG. 2.

FIG. 7 is a flowchart representative of example machine readableinstructions that may be executed to implement power control processingin the first example audience measurement meter of FIG. 3 and/or thesecond example audience measurement meter of FIG. 4.

FIG. 8 is a flowchart representative of example machine readableinstructions that may be executed to implement state reporting in theexample state monitor of FIG. 2.

FIG. 9 is a flowchart representative of example machine readableinstructions that may be executed to implement meter interrogationprocessing in the second example audience measurement meter of FIG. 4.

FIG. 10 is a flowchart representative of example machine readableinstructions that may be executed to implement data reporting in thesecond example audience measurement meter of FIG. 4.

FIG. 11 is a flowchart representative of example machine readableinstructions that may be executed to implement fault determinationprocessing in the example data processing facility of FIG. 5.

FIG. 12 is a block diagram of an example processing system that mayexecute the example machine readable instructions of FIGS. 6-10 and/or11 to implement the example audience measurement system of FIG. 1, theexample state monitor of FIG. 2, the first example audience measurementmeter of FIG. 3, the second example audience measurement meter of FIG. 4and/or the example data processing facility of FIG. 5.

DETAILED DESCRIPTION

Power management methods, apparatus and articles of manufacture foraudience measurement meters are disclosed herein. An example powermanagement method disclosed herein includes determining an activationstate of a media presentation device, and controlling activation of anaudience measurement meter, which is to monitor the media presentationdevice, based on the activation state of the media presentation device.In some examples, the activation state of the media presentation deviceis determined based on measuring power consumption of the mediapresentation device. In some examples, the activation state of the mediapresentation device is determined based on monitoring an audio output ofthe media presentation device. In some examples, controlling activationof the audience measurement meter includes sending a wake-up signal tothe audience measurement meter in response to determining that the mediapresentation device is in an active state, and sending a sleep signal tothe audience measurement meter in response to determining that the mediapresentation device is in an inactive state. In some examples,controlling activation of the audience measurement meter includesdetermining whether the media presentation device has been inactive overa time interval, and when the media presentation device has beeninactive over the time interval, indicating that wake-up andinterrogation of the audience measurement meter to obtain audiencemeasurement data corresponding to the time interval can be skipped(e.g., to permit the audience measurement meter to remain in a sleepstate).

Another example power management method disclosed herein includesobtaining presentation device state data representing an activationstate of a media presentation device being monitored by an audiencemeasurement meter. This example method also includes determining whetherto fault audience measurement data reported by the audience measurementmeter based on the presentation device state data and outage informationdetermined from the audience measurement data. In some examples,determining whether to fault the audience measurement data includesdetermining that the audience measurement data is to be faulted when afirst time interval over which the audience measurement data indicatesan outage occurred overlaps a second time interval over which thepresentation device state data indicates the media presentation devicewas in an active state, and determining that the audience measurementdata is not to be faulted when the first time interval does not overlapthe second interval. In some examples, the presentation device statedata is determined by a state monitor that is separate from the audiencemeasurement meter that determined the audience measurement data.

In at least some prior audience measurement systems, audiencemeasurement meters operate continuously to ensure accurate monitoring ofmedia content presented by monitored media presentation devices at anytime. However, because media presentation devices are often inactive forsubstantial periods of time, such as overnight during normal sleepinghours, such continuous operation of these prior audience measurementmeters can result in unnecessary and/or wasteful power consumption. Incontrast to such prior systems, example power management methods,apparatus and articles of manufacture disclosed herein enable anaudience measurement meter to be activated (e.g., woken-up) anddeactivated (e.g., placed in sleep state) corresponding to a detectedactivation state of a media presentation device being monitored by theaudience measurement meter, thereby improving energy efficiency of theaudience measurement meter. Additionally or alternatively, example powermanagement methods, apparatus and articles of manufacture disclosedherein can determine whether an audience measurement meter has audiencemeasurement data to report and, thus, is to be woken up forinterrogation, or whether the audience measurement meter does not haveaudience measurement data to report and, thus, can be permitted tocontinue operation in a low-power sleep state, which can also yieldefficient energy consumption.

Furthermore, in at least some prior audience measurement systems,audience measurement data provided by an audience measurement meter maybe faulted (e.g., invalidated, discarded, etc.) for an entire monitoringperiod, such as an entire day, if the audience measurement meterexperiences any loss of power or other outage (e.g., such as acommunication outage) for any duration during the monitoring period. Insuch prior systems, the audience measurement data is faulted under thesecircumstances because the data processing facility that is to processthe audience measurement data cannot determine whether or not a mediapresenting device being monitored by the audience measurement meter maystill have presented media content during the gap(s) in the measurementdata resulting from the power loss experienced by the audiencemeasurement meter. In contrast to such prior systems, example powermanagement methods, apparatus and articles of manufacture disclosedherein enable a data processing facility to determine whether the mediapresenting device being monitored by the audience measurement meter wasactive or inactive during a power loss or other outage experienced bythe audience measurement meter (e.g., where a power loss or other outageis indicated by a gap in the audience measurement data reported by theaudience measurement meter). Moreover, if the media presenting device isdetermined to have been inactive while the audience measurement meterexperienced the power loss or other outage, no media content could havebeen presented during the gap(s) in the measurement data resulting fromthe power loss or other outage and, thus, the data processing facilitycan determine that faulting the audience measurement data obtained fromthe audience measurement meter is unnecessary.

Turning to the figures, a block diagram of an example audiencemeasurement system 100 employing power management for audiencemeasurement meters as disclosed herein is illustrated in FIG. 1. Theaudience measurement system 100 of the illustrated example includesthree example monitored sites 105A, 105B and 105C, which may reside atthe same location (e.g., such as an audience members home) or at two ormore different locations. The monitored site 105A includes an examplemedia presentation device 110A and an example audience measurement meter115A to monitor media content presented by the media presentation device110A. Likewise, the monitored site 105B includes an example mediapresentation device 110B and an example audience measurement meter 115Bto monitor media content presented by the media presentation device110B, and the monitored site 105C includes an example media presentationdevice 110C and an example audience measurement meter 115C to monitormedia content presented by the media presentation device 110C. Tosupport power management for the audience measurement meters 115A-C inaccordance with the examples described herein, the monitored sites105A-C include respective example state monitors 120A-C, which aredescribed in greater detail below. Although the audience measurementsystem 100 of the illustrated example includes three monitored sites105A-C, audience measurement meter power management as described hereincan be used in audience measurement systems 100 having any number ofmonitored sites 105A-C.

The example media presentation devices 110A-C can each correspond to anytype of audio, video and/or multimedia presentation device capable ofpresenting media content audibly and/or visually. For example, one ormore of the media presentation devices 110A-C can correspond to arespective television and/or display device that supports the NationalTelevision Standards Committee (NTSC) standard, the Phase AlternatingLine (PAL) standard, the Système Électronique pour Couleur avec Mémoire(SECAM) standard, a standard developed by the Advanced TelevisionSystems Committee (ATSC), such as high definition television (HDTV), astandard developed by the Digital Video Broadcasting (DVB) Project, etc.As another example, one or more of the media presentation devices 110A-Ccan correspond to a multimedia computer system, a personal digitalassistant, a cellular/mobile smartphone, a radio, etc.

The audience measurement meters 115A-C can each correspond to any typeof metering device capable of monitoring media content presented by therespective media presentation devices 110A-C. In FIG. 1, the connectionsbetween the audience measurement meters 115A-C and the respective mediapresentation devices 110A-C are represented by dashed lines because theaudience measurement meters 115A-C may support invasive monitoringinvolving one or more physical connections to the media presentationdevices 110A-C, and/or non-invasive monitoring not involving anyphysical connection to the media presentation devices 110A-C. Forexample, one or more of the audience measurement meters 115A-C canprocess audio signals obtained from a microphone and/or a direct cableconnection to detect content and/or source identifying audio codesand/or audio watermarks embedded in audio portion(s) of the mediacontent presented by the respective one or more of the mediapresentation devices 110A-C. Additionally or alternatively, one or moreof the audience measurement meters 115A-C can process video signalsobtained from a camera and/or a direct cable connection to detectcontent and/or source identifying video codes and/or video watermarksembedded in video portion(s) of the media content presented by therespective one or more of the media presentation devices 110A-C.Additionally or alternatively, one or more of the audience measurementmeters 115A-C can process the aforementioned audio signals and/or videosignals to generate respective audio and/or video signatures from themedia content presented by the respective one or more of the mediapresentation devices 110A-C, which can be compared to referencesignatures to perform source and/or content identification. Other typesof audience measurement meters 115A-C can also be supported by theexample audience measurement meter power management techniques describedherein.

In the audience measurement system 100 of FIG. 1, the media contentmonitoring functionality described above is referred to as site unit(SU) functionality to indicate that the scope of such functionality islimited to the particular monitored site 105A-C in which the respectiveaudience measurement meter 115A-C resides. Additionally, the audiencemeasurement meter 115A of the illustrated example implements home unit(HU) functionality. Home unit functionality involves data logging andforwarding functionality in which the home unit (e.g., the audiencemeasurement meter 115A) interrogates the other site units (e.g., theaudience measurement meters 115B-C) at a particular location (e.g., asubscriber household) to obtain the audience measurement data determinedby each of the site units. Audience measurement data can include, forexample, media content identification information, source identificationinformation, content presentation duration information, audience memberinteraction information (e.g., such as channel and volume changeinformation, digital video recorder command selections, etc.), audiencemember identification information, etc. The home unit then stores theaudience measurement data obtained from the site units, and forwardsthis audience measurement data to a data processing facility forpost-processing (e.g., to credit ratings for particular programs, verifycommercial advertisement broadcasts, etc.).

For example, in the audience measurement system 100, the audiencemeasurement meter 115A provides home unit functionality and, as such,interrogates the audience measurement meters 115B and 115C via anexample network 125 to obtain audience measurement data from themonitored sites 105B and 105C, respectively. The audience measurementmeter 115A then stores and reports this audience measurement data, aswell as the audience measurement data determined by the audiencemeasurement meter 115A itself for the monitored site 105A, via anexample network 130 to an example data processing facility 135. The dataprocessing facility 135 validates the reported audience measurementdata, as described in greater detail below, and performs any appropriatepost-processing of this data. In the illustrated example, the networks125 and 130 can correspond to any type of wired or wireless datanetwork, or combination thereof. Also, the networks 125 and 130 cancorrespond to portions of a common network, or can correspond todistinct networks.

As noted above, the audience measurement system 100 includes the statemonitors 120A-C to support audience measurement meter power managementas described herein. Generally, an example state monitor as describedherein monitors an activation state of a respective media presentationdevice and controls activation of a respective audience measurementmeter based on the monitored activation state of the respective mediapresentation device. For example, the state monitor can set itsrespective audience measurement meter to an enabled state (e.g., anactive mode) when the respective media presentation device is determinedto be active (e.g., on), and can set its respective audience measurementmeter to a sleep state (e.g., a low power mode) when the respectivemedia presentation device is determined to be inactive (e.g., off).Additionally or alternatively, the state monitor can indicate to a homeunit that interrogation of its respective audience measurement meter canbe skipped when the respective media presentation device is determinedto have been inactive (e.g., off) during an interrogation interval(e.g., or other such measurement interval). Additionally oralternatively, the state monitor can determine and report presentationdevice state data representing the monitored activation state of itsrespective media presentation device, and which includes timeinformation specifying an initiation time and duration for eachmonitored state, for use by a data processing facility when validatingaudience measurement data reported by the respective audiencemeasurement meter.

For example, in the audience measurement system 100, the state monitor120A is electrically coupled to a power source 140A. In the illustratedexample, the state monitor 120A couples the power source 140A to themedia presentation device 110A, which is represented by a line 145A. Assuch, the state monitor 120A can monitor the power consumption (e.g., bymonitoring current consumption) associated with the power source 140A todetermine the activation state (e.g., active/on or inactive/off) of themedia presentation device 110A. Based on the monitored activation stateof the media presentation device 110A, the state monitor 120A cancontrol activation of the audience measurement meter 115A, for example,by causing the audience measurement meter 115A to enter an enabled statewhen the state monitor 120A determines that the media presentationdevice 110A is active, and by causing the audience measurement meter115A to enter a sleep state when the state monitor 120A determines thatthe media presentation device 110A is inactive. In the example of FIG.1, the state monitor 120A employs a physical (e.g., wired/cabled)connection 150A to control the audience measurement meter 115A in thismanner. In the illustrated example, the state monitor 120A is alsoconnected to the network 125 and, thus, can report presentation devicestate data representing the monitored activation state of the mediapresentation device 110A, and which includes time information specifyingan initiation time and duration for each monitored state, to the homeunit audience measurement meter 115A for subsequent reporting to thedata processing facility 135. As described in greater detail below, thedata processing facility 135 uses this reported presentation devicestate data, along with outage information determined from the audiencemeasurement data reported by the meter 115A, to determine whether tofault or validate the audience measurement data reported by the meter115A.

Similarly, the state monitor 120B is electrically coupled to a powersource 140B. In the illustrated example, the state monitor 120B couplesthe power source 140B to the media presentation device 110B, which isrepresented by a line 145B. As such, like the state monitor 120A, thestate monitor 120B can monitor the power consumption (e.g., bymonitoring current consumption) associated with the power source 140B todetermine the activation state (e.g., active/on or inactive/off) of themedia presentation device 110B. Based on the monitored activation stateof the media presentation device 110B, the state monitor 120B cancontrol activation of the audience measurement meter 115B, for example,by causing the audience measurement meter 115B to enter an enabled statewhen the state monitor 120B determines that the media presentationdevice 110B is active, and by causing the audience measurement meter115B to enter a sleep state when the state monitor 120B determines thatthe media presentation device 110B is inactive. However, unlike thewired connection 150A employed by the state monitor 120A, the statemonitor 120B employs a wireless connection 150B to control the audiencemeasurement meter 115B in this manner. Also, like the state monitor120A, the state monitor 120B is connected to the network 125 and, thus,can report presentation device state data representing the monitoredactivation state of the media presentation device 110B, and whichincludes time information specifying an initiation time and duration foreach monitored state, to the home unit audience measurement meter 115Afor subsequent reporting to the data processing facility 135. Asdescribed in greater detail below, the data processing facility 135 usesthis reported presentation device state data, along with outageinformation determined from the audience measurement data reported bythe meter 115B, to determine whether to fault or validate the audiencemeasurement data reported by the meter 115B. Additionally oralternatively, in some examples the state monitor 120B communicates withthe home unit audience measurement meter 115A via the network 125 toindicate, based on the monitored activation state of the mediapresentation device 110B, whether interrogation of the audiencemeasurement meter 115B to retrieve its audience measurement data can beskipped during a current interrogation interval (e.g., or other suchmeasurement interval).

In the illustrated example of FIG. 1, the state monitor 120C iselectrically coupled to a power source 140C for powering the statemonitor 120C. However, unlike the arrangements of the state monitors120A-B, the state monitor 120C of the illustrated example does notcouple the power source 140C to the media presentation device 110C.Instead, the power source 145C for the media presentation device 110Cmay be separate from the power source 140C powering the state monitor120C. As such, the state monitor 120C monitors one or more otheroperational aspects of the media presentation device 110C, such as bymonitoring an audio signal 155 output from the media presentation device110C using an example sensor 160, to determine the activation state(e.g., active/on or inactive/off) of the media presentation device 110C.Based on the monitored activation state of the media presentation device110C, the state monitor 120C can control activation of the audiencemeasurement meter 115C, for example, by causing the audience measurementmeter 115C to enter an enabled state when the state monitor 120Cdetermines that the media presentation device 110C is active, and bycausing the audience measurement meter 115C to enter a sleep state whenthe state monitor 120C determines that the media presentation device110C is inactive. The state monitor 120C, like the state monitor 120B,employs a wireless connection 150C to control the audience measurementmeter 115C in this manner. Also, like the state monitors 120A-B, thestate monitor 120C is connected to the network 125 and, thus, can reportpresentation device state data representing the monitored activationstate of the media presentation device 110C, and which includes timeinformation specifying an initiation time and duration for eachmonitored state, to the home unit audience measurement meter 115A forsubsequent reporting to the data processing facility 135. As describedin greater detail below, the data processing facility 135 uses thisreported presentation device state data, along with outage informationdetermined from the audience measurement data reported by the meter115C, to determine whether to fault or validate the audience measurementdata reported by the meter 115C. Additionally or alternatively, in someexamples the state monitor 120C communicates with the home unit audiencemeasurement meter 115A via the network 125 to indicate, based on themonitored activation state of the media presentation device 110C,whether interrogation of the audience measurement meter 115C to retrieveits audience measurement data can be skipped during a currentinterrogation interval (e.g., or other such measurement interval).

A block diagram of an example state monitor 200 that may be used toimplement, for example, any of the state monitors 120A-C of FIG. 1 isillustrated in FIG. 2. The example state monitor 200 of FIG. 2 includesan example presentation device state monitor 205 to monitor anactivation state of a media presentation device, such as one of themedia presentation devices 110A-C. In the illustrated example, the statemonitor 200 can be placed in-line with a power source (e.g., one of thepower sources 140A-B) such that the power source is electrically coupledfrom a power input 210 to a power output 215. If the media presentationdevice is electrically coupled to the power output 215 to obtain powerfrom the power source electrically coupled to the power input 210, thepresentation device state monitor 210 can determine the activation stateof the media presentation device by monitoring power consumptionassociated with power source electrically coupled to the power input210.

For example, the presentation device state monitor 205 can be calibratedwith a first power consumption threshold (e.g., such as a first currentconsumption threshold) corresponding to a minimum expected power(current) consumption when the monitored media presentation device is inan active/on state, and/or a second power consumption threshold (e.g.,such as a second current consumption threshold) corresponding to amaximum expected power (current) consumption when the monitored mediapresentation device is in an inactive/off state. During operation, thepresentation device state monitor 205 can use any appropriate techniqueto monitor the monitored power (current) consumption associated withpower source electrically coupled to the power input 210, and thencompare the monitored power (current) consumption with the first and/orsecond calibrated thresholds. In some examples, the presentation devicestate monitor 205 determines that the monitored media presentationdevice is in an active/on state if the monitored power (current)consumption is greater than the first threshold, and determines that themonitored media presentation device is in an inactive/off state if themonitored power (current) consumption is less than the second threshold.Alternatively, in some examples, the presentation device state monitor205 determines that the monitored media presentation device is in theactive/on state if the monitored power (current) consumption is greaterthan the first threshold, and determines that the monitored mediapresentation device is in the inactive/off state if the monitored power(current) consumption is less than the first threshold. Alternatively,in some examples, the presentation device state monitor 205 determinesthat the monitored media presentation device is in the active/on stateif the monitored power (current) consumption is greater than the secondthreshold, and determines that the monitored media presentation deviceis in the inactive/off state if the monitored power (current)consumption is less than the second threshold.

Additionally or alternatively, the presentation device state monitor 205can detect slope changes in measurements of power (current) consumptionover time to determine when the monitored media presentation device hasbeen switched from an inactive/off state to an active/on state. Forexample, if the presentation device state monitor 205 detects one ormore positive slope changes corresponding to an increase in power(current) consumption over one or more respective (e.g., consecutive)measured time intervals, the presentation device state monitor 205 candetermine that the monitored media presentation device has been switchedfrom an inactive/off state to an active/on state. Conversely, if thepresentation device state monitor 205 detects one or more negative slopechanges corresponding to an decrease in power (current) consumption overone or more respective (e.g., consecutive) measured time intervals, thepresentation device state monitor 205 can determine that the monitoredmedia presentation device has been switched from an active/on state toan inactive/off state.

In some examples, the presentation device state monitor 205 canadditionally or alternatively monitor a digital audio stream output bythe monitored media presentation device and applied to a digital audioinput 220 to determine the activation state of the monitored mediapresentation device. For example, for some media presentation devices, adigital audio stream is present whenever such a device is active/on, andthe digital audio is absent whenever the device is inactive/off. Forsuch media presentation devices, if the digital audio output of themonitored media presentation device is coupled to the digital audioinput 220, the presentation device state monitor 205 can monitor thedigital audio input 220 for the presence of a digital audio stream. If adigital audio stream is present, the presentation device state monitor205 determines that the monitored media presentation device is in anactive/on state. Otherwise, if the digital audio stream is absent, thepresentation device state monitor 205 determines that the monitoredmedia presentation device is in an inactive/off state.

In some examples, the presentation device state monitor 205 canadditionally or alternatively monitor an audio signal emanating from themonitored media presentation device and received by an audio sensor 225,such as a microphone 225, to determine the activation state of themonitored media presentation device. For example, the presentationdevice state monitor 205 can monitor the output of the sensor 225 todetect the presence of an audio signal. If an audio signal is detected(e.g., based on a comparison with a signal energy threshold), thepresentation device state monitor 205 determines that the monitoredmedia presentation device is in an active/on state. Otherwise, if anaudio signal is not detected, the presentation device state monitor 205determines that the monitored media presentation device is in aninactive/off state. Additionally or alternatively, the presentationdevice state monitor 205 can use any one or more of the techniquesdescribed in U.S. Pat. No. 7,882,514, entitled “Display Device On/OffDetection Methods and Apparatus” and issued on Feb. 1, 2011, to processan audio signal output from the sensor 225 to determine an activationstate of a monitored media presentation device. Additionally oralternatively, the presentation device state monitor 205 can employ anyone or more of the techniques described in U.S. Pat. No. 7,882,514 toprocess output signals other than, or in addition to, an audio signal todetermine an activation state of a monitored media presentation device.

The example state monitor 200 of FIG. 2 also includes an example meterpower manager 230 to perform power management for an audiencemeasurement meter (e.g., such as one of the audience measurement meters115A-C) based on the current activation state of an associated mediapresentation device (e.g., such as one of the associated mediapresentation devices 110A-C) as determined by the presentation devicestate monitor 205. Table 1 illustrates an example set of operatingstates for an example audience measurement meter. Although the exampleset of operating states listed in Table 1 correspond to a meterimplementation based on Intel's® Atom™ chipset, this list of operatingstates is representative of typical states in which other processors canbe configured to operate. Furthermore, power management for audiencemeasurement meters as described herein is not limited to being used withmeters having the operating states listed in Table 1, but can be usedwith any meter having two or more operating states in which at least onestate corresponds to an enabled (e.g., on) state, and at least one otheroperating state corresponds to a sleep or other lower power state.

TABLE 1 State Description S0 Enabled state; system is on; centralprocessing unit (CPU) is fully running S1 CPU is stopped; random accessmemory (RAM) is refreshed; system is running in a first low power modeS2 CPU is off (no power); RAM is refreshed; system is running in asecond low power mode that is lower than the first low power mode S3 CPUis off (no power); RAM is in slow refresh state; power supply is in areduced power mode, yielding a third low power mode lower than the firstand second low power modes S4 Hardware is completely off, but systemmemory has been saved to disk S5 Hardware is completely off; operatingsystem has shutdown; system memory is not saved to disk; system if offand a reboot is required to return to a working state

Turning to Table 1, state S3 corresponds to a sleep (or low power) stateinto which a corresponding audience measurement meter (e.g., such as oneof the audience measurement meters 115A-C) can be set in response toapplication of an appropriate sleep signal (or, equivalently, anappropriate sleep command). From state S3 or another low power state,the audience measurement meter can be woken or, in other words,configured to transition to state S0, which corresponds to an enabled(on) state, in response to application of an appropriate wake-up signal(or, equivalently, an appropriate wake-up command). Examples ofappropriate wake-up signals/commands that can be used to wake-up theaudience measurement meter from the sleep state (S3) include one or moreof: (1) an RTC alarm signal that causes the audience measurement meterto transition to the enabled state (S0) upon occurrence of a configuredreal time clock (RTC) alarm; (2) a wake-on-LAN signal that causes theaudience measurement meter to transition to the enabled state (S0) upondetection of data at a local area network (LAN) interface; (3)wake-on-WLAN signal that causes the audience measurement meter totransition to the enabled state (S0) upon detection of data at awireless LAN (WLAN) interface; (4) a wake-on-USB signal that causes theaudience measurement meter to transition to the enabled state (S0) upondetection of data at a universal serial bus (USB) interface; etc.Another example of a wake-up signal/command includes asserting a signalon an appropriately configured input/output (I/O) pin such thatasserting the signal on the I/O pin causes an interrupt to occur, whichtransitions the meter from a sleep state to an enabled state. Yetanother example of a wake-up signal/command includes sending a messageover an appropriately configured bus which, when the message isdetected, causes the meter to transition from a sleep state to anenabled state.

In some examples, the meter power manager 230 uses the currentactivation state of a monitored media presentation device as determinedby the presentation device state monitor 205 to determine whether tosend a sleep signal or an appropriate wake-up signal to an associatedaudience measurement meter. For example, assume without loss ofgenerality that the example state monitor 200 of FIG. 2 is used toimplement the state monitor 120A of FIG. 1. In such an example, furtherassume that the media presentation device 110A in inactive/off, and theaudience measurement meter 115A is in the sleep state (S3). When thepresentation device state monitor 205 detects that the mediapresentation device 110A has transitioned to an active/on state, themeter power manager 230 sends an appropriate wake-up signal to theaudience measurement meter 115A to cause the meter 115A to transition tothe enabled state (S0). For example, the meter power manager 230 cansend a wake-on-LAN signal, send a wake-on-USB signal, send anappropriate bus message and/or assert an appropriate I/O pin via aphysical (e.g., wired/cabled) power control connection 245. Additionallyor alternatively, the meter power manager 230 can send a wake-on-WLANsignal via a wireless power control connection 250. Then, assume thatsometime later the presentation device state monitor 205 detects thatthe media presentation device 110A has transitioned to an inactive/offstate. In response, the meter power manager 230 sends an appropriatesleep signal to the audience measurement meter 115A via one or both ofthe connections 245 and/or 250 to cause the meter 115A to transition tothe sleep state (S3).

The example state monitor 200 of FIG. 2 further includes an examplestate logger 235 to log presentation device state data representing themonitored activation state of the media presentation device asdetermined by the presentation device state monitor 205. For example,the presentation device state data can include information indicatingoccurrences of activation state changes and the resulting activationstate (e.g., active/on, inactive/off, etc.) of the monitored mediapresentation device. Additionally, in the illustrated example, the statemonitor 200 of FIG. 2 includes an example real time clock (RTC) 240, orsimilar clocking/timing mechanism, capable of tracking absolute orrelative time. The state logger 235 uses the RTC 240 to track theinitiation time of each monitored change in the activation state of themonitored media presentation device, and the duration for each resultingmonitored activation state of the monitored media presentation device.In some examples, this timing information is included in thepresentation device state data logged by the state logger 235.Furthermore, the state monitor 200 can include a battery and/or otherbackup power supply (not shown) to permit the presentation device statemonitor 205 to continue monitoring the activation state of a particularmedia presentation device, and to permit the state logger 235 tocontinue logging the presentation device state data, during power outageevents. The presentation device state data can be stored in any dataformat, such as one or more data structures, database entries, etc.

Additionally, the example state monitor 200 of FIG. 2 includes anexample meter state reporter 255 to receive and reply to state queriesreceived via an interface 260 from, for example, a home unit (e.g., suchas the home unit audience measurement meter 115A). Referring to theaudience measurement system 100 of FIG. 1, in some examples, the homeunit audience measurement meter 115A queries the site unit audiencemeasurement meters 115B and 115C at regular interrogation intervals toobtain their stored audience measurement data. If a particular site unitaudience measurement meter 115B-C is in a sleep state (e.g., state S3)at the time of an interrogation query, the particular site unit audiencemeasurement meter 115B-C will wake-up and transition to an enabled state(e.g., state S0) in response to being interrogated. However, if therespective media presentation device 110B being monitored by theparticular site unit audience measurement meter 115B-C has beeninactive/off during the entire interrogation/measurement intervalassociated with the interrogation query (e.g., due to a power outage,lack of device use, etc.), the particular site unit audience measurementmeter 115B-C will have no audience measurement data to report. In suchcircumstances, causing the particular site unit audience measurementmeter 115B-C to wake-up to respond to a received interrogation query isunnecessary and can result in reduced energy efficiency of the meterand/or reduce backup battery life (e.g., if the meter 115B-C isoperating on backup battery power during a power outage and is in asleep state to conserve power, but is then woken unnecessarily).

To avoid querying a particular site unit audience measurement meter115B-C when it has no audience measurement data to report, the home unitaudience measurement meter 115A can first send a state query to thestate monitor 120B-C associated with the particular site unit audiencemeasurement meter 115B-C to obtain information regarding the activationstate of the respective media presentation device 110B-C during theinterrogation/measurement interval. If the state monitor 120B-C replieswith an indication that the respective media presentation device 110B-Chas been inactive during the entire interrogation/measurement intervaland, thus, audience measurement data is unavailable, the home unitaudience measurement meter 115A can skip interrogation of the particularsite unit audience measurement meter 115B-C during the currentinterrogation/measurement interval. If, however, the state monitor120B-C replies with an indication that the respective media presentationdevice 110B-C has been active during at least part of theinterrogation/measurement interval and, thus, audience measurement datamay be available, the home unit audience measurement meter 115A canproceed with interrogating the particular site unit audience measurementmeter 115B-C to obtain its audience measurement data for the currentinterrogation/measurement interval.

Returning to FIG. 2, the meter state reporter 255 can receive such statequeries from a home unit and process the presentation device state datalogged by the state logger 235 to determine whether a media presentationdevice being monitored by the state monitor 200 has been inactive oractive during the current interrogation/measurement interval (e.g.,since the last state query was received). If the presentation devicestate data indicates that the monitored media presentation device hasbeen inactive during the current interrogation/measurement interval, themeter state reporter 255 can reply to the state query with an indicationthat no audience measurement data is available (and, thus, interrogationof the associated audience measurement meter can be skipped) because themedia presentation device has been inactive. However, if thepresentation device state data indicates that the monitored mediapresentation device has been active during at least part of the currentinterrogation/measurement interval, the meter state reporter 255 canreply to the state query with an indication that audience measurementdata may be available (and, thus, interrogation of the associatedaudience measurement meter should be performed) because the mediapresentation device has been active.

In some examples, the meter state reporter 255 additionally oralternatively supports receiving and responding to queries for thepresentation device state data logged by the state logger 235. Forexample, a home unit (e.g., such as the home unit audience measurementmeter 115A) can query the state monitor 200 to obtain its presentationdevice state data for reporting to a data processing facility (e.g.,such as the data processing facility 135). As described in greaterdetail below, the a data processing facility can then use thispresentation device state data to determine whether to fault or validateaudience measurement data being reported by an audience measurementmeter associated with the state monitor 200.

A block diagram of an example site unit audience measurement meter 300that may be used to implement, for example, any of the site unitaudience measurement meters 115B-C of FIG. 1 is illustrated in FIG. 3.The example site unit audience measurement meter 300 of FIG. 3 includesan example monitoring processor 305 to monitor media content presentedby a media presentation device (e.g., such as one of the mediapresentation devices 110B-C) using any invasive or non-invasivemonitoring technique, such as one or more of the monitoring techniquesdescribed above in connection with audience measurement system 100 ofFIG. 1.

The example site unit audience measurement meter 300 of FIG. 3 alsoincludes an example power controller 310 to control power consumption ofthe meter 300, including power consumption associated with themonitoring processor 305, in response to signals/commands received froma state monitor, such as one of the state monitors 120B-C or 200described above. For example, assume that the monitoring processor 305supports operating states such as those listed in Table 1. Then, inresponse to receiving a sleep signal/command from an associated statemonitor, the power controller 310 of the site unit audience measurementmeter 300 can configure the monitoring processor 305 to enter a sleepstate, such as the state S3 of Table 1, or one of the other low powerstates. Furthermore, in response to receiving an activation (e.g.,wake-up) signal/command (e.g., such as a wake-on-LAN signal, awake-on-USB signal, a wake-on-WLAN signal, etc.) from the associatedstate monitor, the power controller 310 can configure the monitoringprocessor 305 to enter an enabled state, such as the state S0 of Table1.

A block diagram of an example implementation of the home unit audiencemeasurement meter 115A of FIG. 1 is illustrated in FIG. 4. The examplehome unit audience measurement meter 115A of FIG. 4 includes an examplemonitoring processor 405 and an example power controller 410, which maybe similar or identical to the respective monitoring processor 305 andpower controller 310 of FIG. 3. The home unit audience measurement meter115A of FIG. 4 also includes an example meter interrogator 415 tointerrogate site units, such as the site unit audience measurementmeters 115B-C, to obtain their stored audience measurement data.Additionally or alternatively, in some examples, the meter interrogator415 is configured to query a state monitor, such as one of the statemonitors 120B-C or 200, associated with the site unit to obtaininformation regarding the media presentation device being monitored bythe site unit before querying the site unit for its audience measurementdata.

Assume, for example and without loss of generality, that a currentinterrogation/measurement interval has expired and the home unitaudience measurement meter 115A is to interrogate the site unit audiencemeasurement meter 115B. In some examples, prior to interrogating themeter 115B, the meter interrogator 415 of the home unit audiencemeasurement meter 115A sends a state query to the state monitor 120B toobtain information regarding the activation state of the mediapresentation device 110B during the current interrogation/measurementinterval. If the state monitor 120B replies with an indication that themedia presentation device 110B has been inactive during the entireinterrogation/measurement interval, the meter interrogator 415 candetermine that no audience measurement data is available at the siteunit audience measurement meter 115B and, thus, skip interrogating themeter 115B for current interrogation/measurement interval. As such, themeter interrogator 415 can avoid causing the site unit audiencemeasurement meter 115B to wake-up and consume additional powerunnecessarily. However, if the state monitor 120B replies with anindication that the media presentation device 110B has been activeduring at least part of the current interrogation/measurement interval,the meter interrogator 415 can determine that audience measurement datamay be available at the site unit audience measurement meter 115B and,thus, interrogate the meter 115B to obtain its audience measurementdata.

A block diagram of an example implementation of the data processingfacility 135 of FIG. 1 is illustrated in FIG. 5. The example dataprocessing facility 135 of FIG. 5 includes an example data receiver 505to receive audience measurement data from one or more home units, suchas the home unit audience measurement meter 115A. Additionally, in someexamples, the data receiver 505 receives presentation device state datarepresenting the activation state(s) of media presentation device(s)associated with the received audience measurement data. In theillustrated example of FIG. 5, the data processing facility 135 alsoincludes an example data processor 510 to perform any type ofpost-processing on the audience measurement data obtained by the datareceiver 505. Examples of post-processing that can be performed by thedata processor 510 includes, but is not limited to, determining ratingsinformation for content presented at the monitored sites 105A-C,performing commercial advertisement verification for commercialsincluded in the media content presented at the monitored sites 105A-C,etc.

Additionally, the example data processing facility 135 of FIG. 5includes an example meter fault determiner 515 to determine whether tofault (e.g., invalidate) audience measurement data obtained by the datareceiver 505 and corresponding to a particular audience measurementmeter. Prior techniques for determining whether to fault audiencemeasurement data generally fault the data for an entire measurementinterval if the audience measurement data indicates that the audiencemeasurement meter experienced a power outage or other outage (e.g., suchas a communication outage) during any portion of the measurementinterval. In contrast to such prior techniques, the fault determiner 515can use the presentation device state data obtained by the data receiver505 to determine whether audience measurement data that indicates thatan outage has occurred is to be faulted or can remain valid even thoughthe outage occurred.

For example, assume without loss of generality that the data receiver505 receives audience measurement data associated with the audiencemeasurement meter 115B, and which indicates that the meter 115Bexperienced outage(s) during one or more outage intervals (e.g., asindicated by gap(s) in the audience measurement data). Such outage(s)can correspond to power outage(s), communication outage(s) correspondingto a disruption in communication between the site unit audiencemeasurement meter 115B and the home unit audience measurement meter115A, other outage(s), or combination(s) thereof. The data receiver 505also receives presentation device state data associated with the statemonitor 120B that indicates occurrences of activation state changes andthe resulting activation states (e.g., active/on, inactive/off, etc.) ofthe monitored media presentation device 110B, as well as the initiationtime of each activation state change and the duration for each resultingmonitored activation state. For example, in the case of a communicationoutage between the site unit audience measurement meter 115B and thehome unit audience measurement meter 115A, the state monitor 120B maystill be able to report its presentation device state data to the homeunit audience measurement meter 115A via a different communicationlink/network. If the fault determiner 515 determines that any timeinterval over which the presentation device state data indicates themedia presentation device 110B was in an active state overlaps with anyoutage interval indicated by the audience measurement data, the faultdeterminer 515 faults the audience measurement data because the meter115B was unable to monitor the media presentation device 110B for atleast some of the time when the latter was active. However, if the faultdeterminer 515 determines that no time interval(s) over which thepresentation device state data indicates the media presentation device110B was in an active state overlaps with any outage interval indicatedby the audience measurement data, then the fault determiner 515 candecide to not fault the audience measurement data because no outageprevented the meter 115B from monitoring the media presentation device110B while the latter was active. Furthermore, in some examples, if thefault determiner 515 detects that a particular audience measurementmeter is experiencing outages over an extended period of time (or anyappropriate interval of time), the fault determiner 515 can causeappropriate repair personnel to be dispatched to the affected monitoredsite to diagnose and repair the cause of the outage.

While example manners of implementing the audience measurement meters115A-C and 300, the state monitors 120A-C and 200, and the dataprocessing facility 135 have been illustrated in FIGS. 2-5, one or moreof the elements, processes and/or devices illustrated in FIGS. 2-5 maybe combined, divided, re-arranged, omitted, eliminated and/orimplemented in any other way. Further, one or more of the exampleaudience measurement meters 115A-C and/or 300, the example statemonitors 120A-C and/or 200, the example data processing facility 135,the example presentation device state monitor 205, the example meterpower manager 230, the example state logger 235, the example RTC 240,the example meter state reporter 255, the example monitoring processors305 and/or 405, the example power controllers 310 and/or 410, theexample meter interrogator 415, the example data receiver 505, theexample data processor 510 and/or the example meter fault determiner 515of FIGS. 2-5 may be implemented by hardware, software, firmware and/orany combination of hardware, software and/or firmware. Thus, forexample, any of the example audience measurement meters 115A-C and/or300, the example state monitors 120A-C and/or 200, the example dataprocessing facility 135, the example presentation device state monitor205, the example meter power manager 230, the example state logger 235,the example RTC 240, the example meter state reporter 255, the examplemonitoring processors 305 and/or 405, the example power controllers 310and/or 410, the example meter interrogator 415, the example datareceiver 505, the example data processor 510 and/or the example meterfault determiner 515 could be implemented by one or more circuit(s),programmable processor(s), application specific integrated circuit(s)(ASIC(s)), programmable logic device(s) (PLD(s)) and/or fieldprogrammable logic device(s) (FPLD(s)), etc. When any of the appendedapparatus claims are read to cover a purely software and/or firmwareimplementation, at least one of the example audience measurement meters115A-C and/or 300, the example state monitors 120A-C and/or 200, theexample data processing facility 135, the example presentation devicestate monitor 205, the example meter power manager 230, the examplestate logger 235, the example RTC 240, the example meter state reporter255, the example monitoring processors 305 and/or 405, the example powercontrollers 310 and/or 410, the example meter interrogator 415, theexample data receiver 505, the example data processor 510 and/or theexample meter fault determiner 515 are hereby expressly defined toinclude a tangible computer readable medium such as a memory, digitalversatile disk (DVD), compact disk (CD), etc., storing such softwareand/or firmware. Further still, the example audience measurement meters115A-C and/or 300, the example state monitors 120A-C and/or 200, theexample data processing facility 135 of FIGS. 2-5 may include one ormore elements, processes and/or devices in addition to, or instead of,those illustrated in FIG. 2-5, and/or may include more than one of anyor all of the illustrated elements, processes and devices.

Flowcharts representative of example machine readable instructions thatmay be executed to implement one or more of the example audiencemeasurement meters 115A-C and/or 300, the example state monitors 120A-Cand/or 200, the example data processing facility 135, the examplepresentation device state monitor 205, the example meter power manager230, the example state logger 235, the example RTC 240, the examplemeter state reporter 255, the example monitoring processors 305 and/or405, the example power controllers 310 and/or 410, the example meterinterrogator 415, the example data receiver 505, the example dataprocessor 510 and/or the example meter fault determiner 515 are shown inFIGS. 6-11. In these examples, the machine readable instructionsrepresented by each flowchart may comprise one or more programs forexecution by a processor, such as the processor 1212 shown in theexample processing system 1200 discussed below in connection with FIG.12. Alternatively, the entire program or programs and/or portionsthereof implementing one or more of the processes represented by theflowcharts of FIGS. 6-11 could be executed by a device other than theprocessor 1212 (e.g., such as a controller and/or any other suitabledevice) and/or embodied in firmware or dedicated hardware (e.g.,implemented by an ASIC, a PLD, an FPLD, discrete logic, etc.). Also, oneor more of the machine readable instructions represented by theflowchart of FIGS. 6-11 may be implemented manually. Further, althoughthe example machine readable instructions are described with referenceto the flowcharts illustrated in FIGS. 6-11, many other techniques forimplementing the example methods and apparatus described herein mayalternatively be used. For example, with reference to the flowchartsillustrated in FIGS. 6-11, the order of execution of the blocks may bechanged, and/or some of the blocks described may be changed, eliminated,combined and/or subdivided into multiple blocks.

As mentioned above, the example processes of FIGS. 6-11 may beimplemented using coded instructions (e.g., computer readableinstructions) stored on a tangible computer readable medium such as ahard disk drive, a flash memory, a read-only memory (ROM), a CD, a DVD,a cache, a random-access memory (RAM) and/or any other storage media inwhich information is stored for any duration (e.g., for extended timeperiods, permanently, brief instances, for temporarily buffering, and/orfor caching of the information). As used herein, the term tangiblecomputer readable medium is expressly defined to include any type ofcomputer readable storage and to exclude propagating signals.Additionally or alternatively, the example processes of FIGS. 6-11 maybe implemented using coded instructions (e.g., computer readableinstructions) stored on a non-transitory computer readable medium, suchas a flash memory, a ROM, a CD, a DVD, a cache, a random-access memory(RAM) and/or any other storage media in which information is stored forany duration (e.g., for extended time periods, permanently, briefinstances, for temporarily buffering, and/or for caching of theinformation). As used herein, the term non-transitory computer readablemedium is expressly defined to include any type of computer readablemedium and to exclude propagating signals. Also, as used herein, theterms “computer readable” and “machine readable” are consideredequivalent unless indicated otherwise.

Example machine readable instructions 600 that may be executed toimplement power management processing in one or more of the statemonitors 120A-C and/or 200 of FIGS. 1-2 are represented by the flowchartshown in FIG. 6. For convenience, and without loss of generality, themachine readable instructions 600 are described in the context ofexecution by the state monitor 200 of FIG. 2 to implement the statemonitor 120A of FIG. 1. As such, in this example, the state monitor 200is performing the role of the state monitor 120A and, thus, isassociated with the media presentation device 110A and the audiencemeasurement meter 115A. With reference to the preceding figures, themachine readable instructions 600 of FIG. 6 begin execution at block 605at which the presentation device state monitor 205 of the state monitor200 monitors and detects an activation state of the media presentationdevice 110A. If the media presentation device 110A is determined to beactive (block 610), then at block 615 the meter power manager 230 of thestate monitor 200 controls activation of the audience measurement meter115A by sending an appropriate activation signal (e.g., wake-up signal)to cause the audience measurement meter 115A to transition to an enabledstate (e.g., state S0 of Table 1). However, if the media presentationdevice 110A is determined to be inactive (block 610), then at block 620the meter power manager 230 controls activation of the audiencemeasurement meter 115A by sending an appropriate sleep signal to causethe audience measurement meter 115A to transition to a sleep state(e.g., state S3 of Table 1). Processing then returns to block 605 toenable the presentation device state monitor 205 to continue monitoringthe activation state of the media presentation device 110A.

Example machine readable instructions 700 that may be executed toimplement power control processing in one or more of the audiencemeasurement meters 115A-C and/or 300 of FIGS. 1, 3 and 4 are representedby the flowchart shown in FIG. 7. For convenience, and without loss ofgenerality, the machine readable instructions 700 are described in thecontext of execution by the audience measurement meter 115A of FIGS. 1and 4. With reference to the preceding figures, the machine readableinstructions 700 of FIG. 7 begin execution at block 705 at which powercontroller 410 of the audience measurement meter 115A receives a powercontrol signal from the state monitor 120A. If the power control signalcorresponds to an activation (wake-up) signal (block 710), then at block715 the power controller 410 sets the audience measurement meter 115A(e.g., by appropriate configuration of its monitoring processor 405) toan enabled state (e.g., state S0 of Table 1). If, however, the powercontrol signal corresponds to a sleep signal (block 710), then at block720 the power controller 410 sets the audience measurement meter 115A(e.g., by appropriate configuration of its monitoring processor 405) toa sleep state (e.g., state S3 of Table 1). Processing then returns toblock 705 to enable the power controller 410 to continue performingpower control for the audience measurement meter 115A.

Example machine readable instructions 800 that may be executed toimplement state reporting in one or more of the state monitors 120A-Cand/or 200 of FIGS. 1-2 are represented by the flowchart shown in FIG.8. For convenience, and without loss of generality, the machine readableinstructions 800 are described in the context of execution by the statemonitor 200 of FIG. 2 to implement the state monitor 120B of FIG. 1. Assuch, in this example, the state monitor 200 is performing the role ofthe state monitor 120B and, thus, is associated with the mediapresentation device 110B and the audience measurement meter 115B. Withreference to the preceding figures, the machine readable instructions800 of FIG. 8 begin execution at block 805 at which the presentationdevice state monitor 205 and the state logger 235 of the state monitor200 monitor and log presentation device state data representing theactivation state of the media presentation device 110B. In someexamples, at block 810 the state logger 235 also logs power outageinterval(s) monitored for the power source 140B powering the statemonitor 200.

At block 815, the meter state reporter 255 determines whether a statequery has been received from the home unit audience measurement meter115A. If a state query has been received (block 815), at block 820 themeter state reporter 255 processes the presentation device state datalogged at block 805 to determine whether the media presentation device110B was inactive during the current interrogation/measurement interval(e.g., corresponding to a current interval of time starting from thelast state query). If the media presentation device 110B was inactiveduring this entire interval (block 825), then at block 830 the meterstate reporter 255 replies to the state query with an indication thatthe media presentation device 110B being monitored by the site unitaudience measurement meter 115B was inactive during the entireinterrogation/measurement interval and, thus, the site unit audiencemeasurement meter 115B has no audience measurement data to report. Inthis case, the home unit audience measurement meter 115A can skipinterrogation of the site unit audience measurement meter 115B for thecurrent interrogation/measurement interval. However, if the mediapresentation device 110B was active during at least part of theinterrogation/measurement interval (block 825), then at block 835 themeter state reporter 255 replies to the state query with an indicationthat the media presentation device 110B was active during theinterrogation/measurement interval and, thus, the site unit audiencemeasurement meter 115B may have audience measurement data to report. Inthis case, the home unit audience measurement meter 115A proceeds withinterrogation of the site unit audience measurement meter 115B to obtainits audience measurement data for the current interrogation/measurementinterval.

Example machine readable instructions 900 that may be executed toimplement meter interrogation processing in the home unit audiencemeasurement meter 115A of FIGS. 1 and 4 are represented by the flowchartshown in FIG. 9. For convenience, and without loss of generality, themachine readable instructions 900 are described in the context ofexecution by the home unit audience measurement meter 115A tointerrogate the site unit audience measurement meter 115B of FIG. 1.With reference to the preceding figures, the machine readableinstructions 900 of FIG. 9 begin execution at block 905 at which themeter interrogator 415 of the home unit audience measurement meter 115Aqueries the state monitor 120B associated with the site unit audiencemeasurement meter 115B to determine whether the media presentationdevice 110B was active during the current interrogation/measurementinterval and, thus, to determine whether the site unit audiencemeasurement meter 115B has any audience measurement data to report. Atblock 910 the meter interrogator 415 evaluates the response receivedfrom the state monitor 120B. If the response indicates that the mediapresentation device 110B was inactive during the entireinterrogation/measurement interval and, thus, no audience measurementdata is available (block 910), then at block 915 the meter interrogator415 skips (e.g., does not perform) waking-up and interrogation of thesite unit audience measurement meter 115B. In some example, processingproceeds to block 920 at which the meter interrogator 415 further sendsa sleep signal to the site unit audience measurement meter 115B toenable the meter 115B to enter a sleep state (e.g., state S3 of Table 1)if, for example, the meter 115B has not otherwise been enabled toperform other processing.

However, if the response indicates that the media presentation device110B was active during the interrogation/measurement interval and, thus,audience measurement data may be available (block 910), then at block925 the meter interrogator 415 sends an appropriate activation signal(e.g., wake-up signal) to cause the site unit audience measurement meter115B to transition to an enabled state (e.g., state S0 of Table 1). Atblock 930, the meter interrogator 415 then queries the site unitaudience measurement meter 115B to obtain any audience measurement datato be reported. After the audience measurement data is received from thesite unit audience measurement meter 115B (block 935), at block 920 themeter interrogator 415 sends a sleep signal to the site unit audiencemeasurement meter 115B to enable the meter 115B to enter a sleep state(e.g., state S3 of Table 1) if the meter 115B has not otherwise beenenabled to perform other processing.

Example machine readable instructions 1000 that may be executed toimplement data reporting in the home unit audience measurement meter115A of FIGS. 1 and 4 are represented by the flowchart shown in FIG. 10.With reference to the preceding figures, the machine readableinstructions 1000 of FIG. 10 begin execution at block 1005 at which themeter interrogator 415 of the home unit audience measurement meter 115Aqueries the state monitors 120A, 120B and 120C for presentation devicestate data representing the activation state history for the respectivemedia presentation devices 110A, 110B and 110C being monitored by therespective site unit audience measurement meters 115A, 115B and 115C. Atblock 1010, the home unit audience measurement meter 115A interrogatesthe site unit audience measurement meters 115B and 115C to obtain theirrespective audience measurement data, as appropriate (e.g., using theexample machine readable instructions 900 of FIG. 9). At block 1015, thehome unit audience measurement meter 115A reports the presentationdevice state data obtained from the state monitors 120A-C and theaudience measurement data obtained from the site unit audiencemeasurement meters 115B-C, as well as the audience measurement datadetermined by the home unit audience measurement meter 115A itself, tothe data processing facility 135. As noted above, the audiencemeasurement data reported at block 1015 includes power outage and/orother outage information for the respective audience measurement meters115A-C (e.g., in the form of gaps in the audience measurement data forthe respective meters 115A-C).

Example machine readable instructions 1100 that may be executed toimplement fault determination processing in the data processing facility135 of FIGS. 1 and 5 are represented by the flowchart shown in FIG. 11.With reference to the preceding figures, the machine readableinstructions 1100 of FIG. 11 begin execution at block 1105 at which thedata receiver 505 of the data processing facility 135 receivesrespective audience measurement data obtained from the audiencemeasurement meters 115A-C, and also respective presentation device statedata obtained from the state monitors 120A-C. For convenience, andwithout loss of generality, the remainder of the machine readableinstructions 1100 are described from the perspective of processing theaudience measurement data obtained from the audience measurement meter115A and processing the presentation device state data obtained from thestate monitor 120A. As such, at block 1110 the meter fault determiner515 of the data processing facility 135 determines whether the audiencemeasurement data obtained from the audience measurement meter 115Aindicates that the meter 115A experienced an outage (e.g., correspondingto a gap in the measurement data). If no outage occurred (block 1110),then the meter fault determiner 515 determines that the audiencemeasurement data is valid and, at block 1115, the data processor 510 ofthe data processing facility 135 performs any appropriatepost-processing on the audience measurement data obtained from theaudience measurement meter 115A.

However, if the audience measurement data indicates that an outageoccurred (block 1110), then at block 1120 the meter fault determiner 515determines whether any outage interval determined from the audiencemeasurement data overlaps (at least partially) with any time intervalover which the presentation device state data obtained from the statemonitor 120A indicates that the media presentation device 110A wasactive. If there is any overlap of these time intervals (block 1120),then at block 1125 the meter fault determiner 515 faults the audiencemeasurement data obtained from the audience measurement meter 115A. If,however, there is no overlap between any outage time intervalsdetermined from the audience measurement data and the active device timeintervals determined from the presentation device state data (block1120), then at block 1130 the meter fault determiner 515 does not faultthe audience measurement data obtained from the audience measurementmeter 115A. In this case, the meter fault determiner 515 determines thatthe audience measurement data is valid, and processing proceeds to block1115 at which the data processor 510 performs any appropriatepost-processing on the audience measurement data.

FIG. 12 is a block diagram of an example processing system 1200 capableof implementing the apparatus and methods disclosed herein. Theprocessing system 1200 can be, for example, a server, a personalcomputer, a personal digital assistant (PDA), an Internet appliance, aDVD player, a CD player, a digital video recorder, a personal videorecorder, a set top box, or any other type of computing device.

The system 1200 of the instant example includes a processor 1212 such asa general purpose programmable processor. The processor 1212 includes alocal memory 1214, and executes coded instructions 1216 present in thelocal memory 1214 and/or in another memory device. The processor 1212may execute, among other things, the machine readable instructionsrepresented in FIGS. 6-11. The processor 1212 may be any type ofprocessing unit, such as one or more Intel® microprocessors from theAtom™ family, the Pentium® family, the Itanium® family and/or theXScale® family, one or more microcontrollers from the ARM® and/or PICOfamilies of microcontrollers, etc. Of course, other processors fromother families are also appropriate.

The processor 1212 is in communication with a main memory including avolatile memory 1218 and a non-volatile memory 1220 via a bus 1222. Thevolatile memory 1218 may be implemented by Static Random Access Memory(SRAM), Synchronous Dynamic Random Access Memory (SDRAM), Dynamic RandomAccess Memory (DRAM), RAMBUS Dynamic Random Access Memory (RDRAM) and/orany other type of random access memory device. The non-volatile memory1220 may be implemented by flash memory and/or any other desired type ofmemory device. Access to the main memory 1218, 1220 is typicallycontrolled by a memory controller (not shown).

The processing system 1200 also includes an interface circuit 1224. Theinterface circuit 1224 may be implemented by any type of interfacestandard, such as an Ethernet interface, a universal serial bus (USB),and/or a third generation input/output (3GIO) interface.

One or more input devices 1226 are connected to the interface circuit1224. The input device(s) 1226 permit a user to enter data and commandsinto the processor 1212. The input device(s) can be implemented by, forexample, a keyboard, a mouse, a touchscreen, a track-pad, a trackball,an isopoint and/or a voice recognition system.

One or more output devices 1228 are also connected to the interfacecircuit 1224. The output devices 1228 can be implemented, for example,by display devices (e.g., a liquid crystal display, a cathode ray tubedisplay (CRT)), by a printer and/or by speakers. The interface circuit1224, thus, typically includes a graphics driver card.

The interface circuit 1224 also includes a communication device such asa modem or network interface card to facilitate exchange of data withexternal computers via a network (e.g., an Ethernet connection, adigital subscriber line (DSL), a telephone line, coaxial cable, acellular telephone system, etc.).

The processing system 1200 also includes one or more mass storagedevices 1230 for storing machine readable instructions and data.Examples of such mass storage devices 1230 include floppy disk drives,hard drive disks, compact disk drives and digital versatile disk (DVD)drives. In some examples, the mass storage device 1230 may store thepresentation device state data logged by the example state logger 235 ofthe example state monitor 220. Additionally or alternatively, in someexamples the volatile memory 1218 may store the presentation devicestate data logged by the example state logger 235.

The coded instructions 1232 of FIGS. 6-11 may be stored in the massstorage device 1230, in the volatile memory 1218, in the non-volatilememory 1220, in the local memory 1214 and/or on a removable storagemedium, such as a CD or DVD 1232.

As an alternative to implementing the methods and/or apparatus describedherein in a system such as the processing system of FIG. 12, the methodsand or apparatus described herein may be embedded in a structure such asa processor and/or an ASIC (application specific integrated circuit).

Finally, although certain example methods, apparatus and articles ofmanufacture have been described herein, the scope of coverage of thispatent is not limited thereto. On the contrary, this patent covers allmethods, apparatus and articles of manufacture fairly falling within thescope of the appended claims either literally or under the doctrine ofequivalents.

What is claimed is:
 1. A method comprising: obtaining, by executing aninstruction with a processor, presentation device state datarepresenting an activation state history of a media presentation device,the presentation device state data including time information;obtaining, by executing an instruction with the processor, audiencemeasurement data reported by an audience measurement meter monitoringpresentation of media by the media presentation device; and in responseto the audience measurement data indicating the audience measurementmeter experienced an outage, determining, by executing an instructionwith the processor, whether the audience measurement data is to befaulted based on a comparison of the activation state history of themedia presentation device and outage information for the audiencemeasurement meter determined from the audience measurement data.
 2. Themethod as defined in claim 1, wherein the determining of whether theaudience measurement data is to be faulted includes: determining thatthe audience measurement data is to be faulted when a first timeinterval over which the audience measurement data indicates the outageoccurred overlaps a second time interval over which the presentationdevice state data indicates the media presentation device was active;and determining that the audience measurement data is not to be faultedwhen the first time interval does not overlap the second interval. 3.The method as defined in claim 1, wherein the determining of whether theaudience measurement data is to be faulted includes: determining thatthe audience measurement data is to be faulted when a time interval overwhich the audience measurement data indicates the outage occurredoverlaps a time interval over which the presentation device state dataindicates the media presentation device was active; and determining thatthe audience measurement data is not to be faulted when no time intervalover which the audience measurement data indicates the outage occurredoverlaps another time interval over which the presentation device statedata indicates the media presentation device was active.
 4. The methodas defined in claim 1, wherein the presentation device state data isdetermined by a device separate from the audience measurement meter thatreported the audience measurement data.
 5. The method as defined inclaim 1, wherein the outage information indicates an interval of timeover which the audience measurement meter experienced a power outage. 6.The method as defined in claim 1, wherein the audience measurement meteris a first audience measurement meter, and the outage informationindicates an interval of time over which the first audience measurementmeter experienced a communication outage with a second audiencemeasurement meter.
 7. A non-transitory computer readable mediumcomprising computer readable instructions which, when executed, cause aprocessor to at least: obtain presentation device state datarepresenting an activation state history of a media presentation device,the presentation device state data including time information; obtainaudience measurement data reported by an audience measurement meter thatis to monitor presentation of media by the media presentation device;and in response to the audience measurement data indicating the audiencemeasurement meter experienced an outage, determine whether the audiencemeasurement data is to be faulted based on a comparison of theactivation state history of the media presentation device and outageinformation for the audience measurement meter determined from theaudience measurement data.
 8. The non-transitory computer readablemedium as defined in claim 7, wherein to determine whether the audiencemeasurement data is to be faulted, the instructions, when executed,further cause the processor to: determine that the audience measurementdata is to be faulted when a first time interval over which the audiencemeasurement data indicates the outage occurred overlaps a second timeinterval over which the presentation device state data indicates themedia presentation device was active; and determine that the audiencemeasurement data is not to be faulted when the first time interval doesnot overlap the second interval.
 9. The non-transitory computer readablemedium as defined in claim 7, wherein to determine whether the audiencemeasurement data is to be faulted, the instructions, when executed,further cause the processor to: determine that the audience measurementdata is to be faulted when a time interval over which the audiencemeasurement data indicates the outage occurred overlaps a time intervalover which the presentation device state data indicates the mediapresentation device was active; and determine that the audiencemeasurement data is not to be faulted when no time interval over whichthe audience measurement data indicates the outage occurred overlapsanother time interval over which the presentation device state dataindicates the media presentation device was active.
 10. Thenon-transitory computer readable medium as defined in claim 7, whereinthe presentation device state data is determined by a device separatefrom the audience measurement meter that reported the audiencemeasurement data.
 11. The non-transitory computer readable medium asdefined in claim 7, wherein the outage information indicates an intervalof time over which the audience measurement meter experienced a poweroutage.
 12. The tangible computer readable medium as defined in claim 7,wherein the audience measurement meter is a first audience measurementmeter, and the outage information indicates an interval of time overwhich the first audience measurement meter experienced a communicationoutage with a second audience measurement meter.
 13. An apparatuscomprising: a data receiver to: obtain presentation device state datarepresenting an activation state history of a media presentation device,the presentation device state data including time information; andobtain audience measurement data reported by an audience measurementmeter that is to monitor presentation of media by the media presentationdevice; and a processor to determine whether the audience measurementdata is to be faulted in response to the audience measurement dataindicating the audience measurement meter experienced an outage, theprocessor to determine whether the audience measurement data is to befaulted based on a comparison of the activation state history of themedia presentation device and outage information for the audiencemeasurement meter determined from the audience measurement data.
 14. Theapparatus as defined in claim 13, wherein to determine whether theaudience measurement data is to be faulted, the processor is to:determine that the audience measurement data is to be faulted when afirst time interval over which the audience measurement data indicatesthe outage occurred overlaps a second time interval over which thepresentation device state data indicates the media presentation devicewas active; and determine that the audience measurement data is not tobe faulted when the first time interval does not overlap the secondinterval.
 15. The apparatus as defined in claim 13, wherein to determinewhether the audience measurement data is to be faulted, the processor isto: determine that the audience measurement data is to be faulted when atime interval over which the audience measurement data indicates theoutage occurred overlaps a time interval over which the presentationdevice state data indicates the media presentation device was active;and determine that the audience measurement data is not to be faultedwhen no time interval over which the audience measurement data indicatesthe outage occurred overlaps another time interval over which thepresentation device state data indicates the media presentation devicewas active.
 16. The apparatus as defined in claim 13, wherein thepresentation device state data is determined by a device separate fromthe audience measurement meter that reported the audience measurementdata.
 17. The apparatus as defined in claim 13, wherein the outageinformation indicates an interval of time over which the audiencemeasurement meter experienced a power outage.
 18. The apparatus asdefined in claim 13, wherein the audience measurement meter is a firstaudience measurement meter, and the outage information indicates aninterval of time over which the first audience measurement meterexperienced a communication outage with a second audience measurementmeter.